“Luc Besson Says Lucy 2 Is Unlikely” .That was clearly … but for Mathilda?
Luc wants “Mathilda”, Natalie also. He never said that the sequel is unlikely. He is just waiting for the best opportunity.

“It’s not the first time that Luc Besson has been approached to extend an on-screen universe that he’d prefer to leave alone. The director has been asked repeatedly to make a sequel to his smash hit Leon: The Professional, possibly telling the story of Natalie Portman’s character. So far, it’s not meant to be. But Besson wisely keeps all the doors open, saying if the right idea hits him, he might pursue more stories with these interesting and original characters. What a novel concept. Doing a sequel because the story dictates it – not because a studio wants to fill its bank vaults.”http://www.cinemablend.com/new/Luc-Besson-Says-Lucy-2-Unlikely-66905.html